常用窗函数c++的实现
/*
* Copyright (c) 2008-2011 Zhang Ming (M. Zhang), zmjerry@https://www.wendangku.net/doc/8a13929327.html,
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation, either version 2 or any later version.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details. A copy of the GNU General Public License is available at:
* https://www.wendangku.net/doc/8a13929327.html,/licensing/licenses
*/
/*****************************************************************************
* window.h
*
* This file includes seven usually used windows in signal processing:
* Rectangle Bartlett Hanning Hamming
* Blackman Kaiser Gauss
* All of them are same to those in "Matlab".
*
* Zhang Ming, 2010-01, Xi'an Jiaotong University.
*****************************************************************************/
#ifndef WINDOW_H
#define WINDOW_H
#include
namespace splab
{
template
template
Type, Type );
template
template
template
template
template
template
template
template
#include
}
// namespace splab
#endif
// WINDOW_H
实现文件：
/*
* Copyright (c) 2008-2011 Zhang Ming (M. Zhang), zmjerry@https://www.wendangku.net/doc/8a13929327.html,
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation, either version 2 or any later version.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provid
ed that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details. A copy of the GNU General Public License is available at:
* https://www.wendangku.net/doc/8a13929327.html,/licensing/licenses
*/
/*****************************************************************************
* window.h
*
* Implementation for window function.
*
* Zhang Ming, 2010-01, Xi'an Jiaotong University.
*****************************************************************************/
/**
* Get the specified window.
*/
template
Vector
{
if( wnName == "Rectangle" )
return rectangle( N, amp );
else if( wnName == "Bartlett" )
return bartlett( N, amp );
else if( wnName == "Hanning" )
return hanning( N, amp );
else if( wnName == "Hamming" )
return hamming( N, amp );
else if( wnName == "Blackman" )
return blackman( N, amp );
else
{
cerr << "No such type window!" << endl;
return Vector
}
}
template
Vector
{
if( wnName=="Kaiser" )
return kaiser( N, alpha, amp );
else if( wnName=="Gauss" )
return gauss( N, alpha, amp );
else
{
cerr << "No such type window!" << endl;
return Vector
}
}
/**
* Calculates rectangle window coefficients.
*/
template
Vector
{
Vector
for( int i=0; i<(N+1)/2; ++i )
{
win[i] = amp;
win[N-1-i] = win[i];
}
return win;
}
/**
* Calculates bartlett window coefficients.
*/
template
Vector
{
Vector
for( int i=0; i<(N+1)/2; ++i )
{
win[i] = amp*2*i / (N-1);
win[N-1-i] = win[i];
}
return win;
}
/**
* Calculates hanning window coefficients.
*/
template
Vector
{
Vector
for( int i=0; i<(N+1)/2; ++i )
{
win[i] = amp * Type( 0.5 - 0.5*cos(TWOPI*i/(N-1)) );
win[N-1-i] = win[i];
}
return win;
}
/**
* Calculates hamming window coefficients.
*/
te
mplate
Vector
{
Vector
for( int i=0; i<(N+1)/2; ++i )
{
win[i] = amp * Type( 0.54 - 0.46*cos(TWOPI*i/(N-1.0)) );
win[N-1-i] = win[i];
}
return win;
}
/**
* Calculates hamming window coefficients.
*/
template
Vector
{
Vector
for( int i=0; i<(N+1)/2; ++i )
{
win[i] = amp * Type ( 0.42 - 0.50*cos(TWOPI*i/(N-1.0))
+ 0.08*cos(2*TWOPI*i/(N-1.0)) );
win[N-1-i] = win[i];
}
return win;
}
/**
* Calculates hamming window coefficients.
*/
template
Vector
{
Vector
for( int i=0; i<(N+1)/2; ++i )
{
Type beta = 2*alpha * Type( sqrt(i*(N-i-1.0))/(N-1.0) );
win[i] = amp * I0(beta) / I0(alpha);
win[N-1-i] = win[i];
}
return win;
}
/**
* Calculates gauss window coefficients. "Alpha: is a optional parameter,
* the default value is 2.5.
*/
template
Vector
{
Vector
Type center = (N-1)/Type(2);
for( int i=0; i<(N+1)/2; ++i )
{
Type tmp = alpha*(i-center) / center;
win[i] = amp * Type( exp(-0.5*tmp*tmp ) );
win[N-1-i] = win[i];
}
return win;
}
/**
* The zeroth N modified Bessel function of the first kind.
*/
template
Type I0( Type alpha )
{
double J = 1.0,
K = alpha / 2.0,
iOld = 1.0,
iNew;
bool converge = false;
// Use series expansion definition of Bessel.
for( int i=1; i
J *= K/i;
iNew = iOld + J*J;
if( (iNew-iOld) < EPS )
{
converge = true;
break;
}
iOld = iNew;
}
if( !converge )
return Type(0);
return Type(iNew);
}
测试代码：
/*****************************************************************************
* window_test.cpp
*
* Windows function testing.
*
* Zhang Ming, 2010-01, Xi'an Jiaotong University.
*****************************************************************************/
#define BOUNDS_CHECK
#include
#include
#include
using namespace std;
using namespace splab;
typedef double Type;
int main()
{
int N = 5;
Type A = 1.0;
cout << setiosflags(ios::fixed) << setprecision(4);
cout << "Rectangle window : " << rectangle(N,A) << endl;
cout << "Bartlett window : " << bartlett(N,A) << endl;
cout << "Hanning window : " << hanning(N,A) << endl;
cout << "Hamming window : " << hamming(N,A) << endl;
cout << "Blackman window : " << blackman(N,A) << end
l;
cout << "Kaiser window : " << kaiser(N,Type(8/PI),A) << endl;
cout << "Gauss window : " << gauss(N,Type(2.5),A) << endl;
cout << "Rectangle window : " << window("Rectangle",N,A) << endl;
cout << "Bartlett window : " << window("Bartlett",N,A) << endl;
cout << "Hanning window : " << window("Hanning",N,A) << endl;
cout << "Hamming window : " << window("Hamming",N,A) << endl;
cout << "Blackman window : " << window("Blackman",N,A) << endl;
cout << "Kaiser window : " << window("Kaiser",N, Type(8/PI),A) << endl;
cout << "Gauss window : " << window("Gauss",N,Type(2.5),A) << endl;
return 0;
}
运行结果：
Rectangle window : size: 5 by 1
1.0000
1.0000
1.0000
1.0000
1.0000
Bartlett window : size: 5 by 1
0.0000
0.5000
1.0000
0.5000
0.0000
Hanning window : size: 5 by 1
0.0000
0.5000
1.0000
0.5000
0.0000
Hamming window : size: 5 by 1
0.0800
0.5400
1.0000
0.5400
0.0800
Blackman window : size: 5 by 1
-0.0000
0.3400
1.0000
0.3400
-0.0000
Kaiser window : size: 5 by 1
0.2933
0.7742
1.0000
0.7742
0.2933
Gauss window : size: 5 by 1
0.0439
0.4578
1.0000
0.4578
0.0439
Rectangle window : size: 5 by 1
1.0000
1.0000
1.0000
1.0000
1.0000
Bartlett window : size: 5 by 1
0.0000
0.5000
1.0000
0.5000
0.0000
Hanning window : size: 5 by 1
0.0000
0.5000
1.0000
0.5000
0.0000
Hamming window : size: 5 by 1
0.0800
0.5400
1.0000
0.5400
0.0800
Blackman window : size: 5 by 1
-0.0000
0.3400
1.0000
0.3400
-0.0000
Kaiser window : size: 5 by 1
0.2933
0.7742
1.0000
0.7742
0.2933
Gauss window : size: 5 by 1
0.0439
0.4578
1.0000
0.4578
0.0439
Process returned 0 (0x0) execution time : 0.140 s
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